1. Field of the invention
The present invention is related to a pressing structure of a hole-punching unit, and more particularly, to a multi-hole-punching unit for binding books, and still more particularly, to a pressing structure for fastening a hole-punching assembly to facilitate the process of switching and maintaining the hole-punching assembly.
2. Description of the Prior Art
As of now, hole-punching unit is used to punch holes on a stack of papers to bind papers into a book. Due to different binding styles and requirements, a multi-hole-punching unit is provided to punch a plurality of holes on a stack of papers at a time.
Prior art multi-hole-punching unit is operated by driving a plurality of tool holders disposed at the hole-punching assembly to move back and forth to complete the hole-punching operation on a stack of papers. As the sheet number and the weight of papers vary, the thickness of the paper stack will be different, and configurations such as different binding requirements, gap between each hole and number of holes are different as well. In this case, user has to find a hole-punching assembly having suitable tool holders according to sheet number and paper thickness, and also tries to reduce or increase the number of tool holders based on number of holes and their relative positions. Besides, when the hole-punching assembly malfunctions or the tool-holders are worn down so that the hole-punching unit can't carry out its function, it requires some maintenance and fixing works to be done. However, in prior art hole-punching unit, hole-punching assembly is fixed by complicated structure, it is often necessary to use auxiliary tools to remove the hole-punching assembly, thereby causing inconvenience in maintenance operation.
In view of the above-described deficiencies, after years of constant effort in research, the inventor of this invention has consequently developed and proposed a new pressing structure for hole-punching unit disclosed in the present invention.